The invention concerns a periscope at the hatchway of a combat vehicle. The hatchway is closed by a hatch that comprises two components. One component is above the other at least when the hatchway is closed. The upper component is positioned over the upper edge of the hatchway and moves parallel to the plane that the hatch slides back and forth in. The lower component moves perpendicular to that plane. The periscope comprises two sections. The lower section is fastened to the vehicle and extends into its interior. The upper section extends through and slides back and forth along with the upper hatch component. The upper and lower periscope sections remain in optical alignment and contact as long as the upper hatch component is in its hatchway-closing position.
A periscope of this genus, comprising a lower section fastened to the vehicle and an upper section that slides back and forth with the upper hatch component, is described in German Patent 3 305 882 for example. Two-section periscopes have the disadvantage that dirt can penetrate between the upper and lower sections.